NAME¶

lttng-save - Save LTTng recording session configurations

SYNOPSIS¶

lttng [GENERAL OPTIONS] save [--force] [--output-path=DIR]


      [--no-triggers] [--all | SESSION]

DESCRIPTION¶

The lttng save command saves to files the configurations of:

With the SESSION argument

Without the SESSION argument

See lttng-concepts(7) to learn more about recording sessions.

Use the save command in conjunction with the lttng-load(1) command to save and restore the complete configurations of recording sessions.

The save command does NOT save tracing data, only the recording session parameters, including the event record channel and recording event rule configurations.

Each saved recording session configuration file also contains all the triggers (see lttng-add-trigger(1)) of the connected session daemon for your Unix user, or for all users if your Unix user is root, even those triggers which aren’t directly related to the targeted recording session(s). This is needed because, for example, an “increment map value” trigger action targets a map channel of a specific recording session, but the trigger itself is a session daemon-wide object.

The lttng-load(1) command makes the loading Unix user the owner of every loaded recording session and trigger, regardless of their original owner.

Avoid saving any trigger with the --no-triggers option. Note, however, that without saved triggers, the lttng-load(1) command won’t restore, amongst other things, the “increment map value” actions for the loaded recording session(s).

The default output directory path is $LTTNG_HOME/.lttng/sessions ($LTTNG_HOME defaults to $HOME). Override the default output directory path with the --output-path option. Each recording session configuration file is named SNAME.lttng, where SNAME is the original recording session name.

By default, the save command does NOT overwrite existing recording session configuration files: the command fails. Allow the save command to overwrite existing recording session configuration files with the --force option.

See the “EXAMPLES” section below for usage examples.

OPTIONS¶

See lttng(1) for GENERAL OPTIONS.

-a, --all

-f, --force

--no-triggers

-o DIR, --output-path=DIR

EXIT STATUS¶

0

1

2

3

4

ENVIRONMENT¶

LTTNG_ABORT_ON_ERROR

LTTNG_HOME

LTTNG_LIST_LEGACY

LTTNG_MAN_BIN_PATH

LTTNG_NO_UTF_8

LTTNG_SESSION_CONFIG_XSD_PATH

LTTNG_SESSIOND_PATH

LTTNG_TERM_COLOR

NO_COLOR

FILES¶

$LTTNG_HOME/.lttngrc

$LTTNG_HOME/lttng-traces

$LTTNG_HOME/.lttng

$LTTNG_HOME/.lttng/sessions

/etc/lttng/sessions

Note

EXAMPLES¶

Example 1. Save all the recording session configurations to the default output directory.

$ lttng save

Example 2. Save a specific recording session configuration to a specific output directory.

$ lttng save my-session --output-path=/path/to/sessions

Example 3. Allow LTTng to overwrite existing recording session configuration files when saving.

$ lttng save --force

Example 4. Save the configuration of a specific recording session without saving any trigger.

$ lttng save my-session --no-triggers

RESOURCES¶

COPYRIGHT¶

This program is part of the LTTng-tools project.

LTTng-tools is distributed under the GNU General Public License version 2 <http://www.gnu.org/licenses/old-licenses/gpl-2.0.en.html>. See the LICENSE <https://github.com/lttng/lttng-tools/blob/master/LICENSE> file for details.

THANKS¶

Special thanks to Michel Dagenais and the DORSAL laboratory <http://www.dorsal.polymtl.ca/> at École Polytechnique de Montréal for the LTTng journey.

Also thanks to the Ericsson teams working on tracing which helped us greatly with detailed bug reports and unusual test cases.

SEE ALSO¶

lttng(1), lttng-add-trigger(1), lttng-load(1), lttng-concepts(7)